Lipid metabolism in fish (mainly Trichogaster), in particular conversion of fatty acids, fatty alcohols and wax esters, is being studied in vivo and in vitro. Nutritional studies are directed mainly to the metabolism of polyunsaturated lipids in the adult fish and the fry. The enzymatic reactions specific for particular tissues will be characterized. Some exploratory work will concern the possible correlation of polyunsaturated acids to furan fatty acids, and the accumulation and turnover of lipid soluble toxic chemicals in the tissues.